Buggy code:
public class HostXml extends CommonXml { public HostXml ( final ModuleLoader loader ) { } @ Override public void readElement ( final XMLExtendedStreamReader reader , final List < ModelNode > operationList ) throws XMLStreamException { } @ Override public void writeContent ( final XMLExtendedStreamWriter writer , final ModelMarshallingContext context ) throws XMLStreamException { } private void readHostElement ( final XMLExtendedStreamReader reader , final ModelNode address , final List < ModelNode > list ) throws XMLStreamException { } private void addLocalHost ( final ModelNode address , final List < ModelNode > operationList , final String hostName ) { } private void parseDomainController ( final XMLExtendedStreamReader reader , final ModelNode address , final List < ModelNode > list ) throws XMLStreamException { } private void parseRemoteDomainController ( final XMLExtendedStreamReader reader , final ModelNode address , final List < ModelNode > list ) throws XMLStreamException { } private void parseJvms ( final XMLExtendedStreamReader reader , final ModelNode address , final List < ModelNode > list ) throws XMLStreamException { } private void parseServers ( final XMLExtendedStreamReader reader , final ModelNode address , final List < ModelNode > list ) throws XMLStreamException { } private void parseServer ( final XMLExtendedStreamReader reader , final ModelNode parentAddress , final List < ModelNode > list , final Set < String > serverNames ) throws XMLStreamException { String name = null ; String group = null ; Boolean start = null ; final int count = reader . getAttributeCount ( ) ; for ( int i = 0 ; i < count ; i ++ ) { final String value = reader . getAttributeValue ( i ) ; if ( ! ( ParseUtils . isNoNamespaceAttribute ( reader , i ) ) ) { throw ParseUtils . unexpectedAttribute ( reader , i ) ; } else { final Attribute attribute = Attribute . forName ( reader . getAttributeLocalName ( i ) ) ; switch ( attribute ) { case NAME : { if ( ! ( serverNames . add ( value ) ) ) { throw new XMLStreamException ( ( "Duplicate<seq2seq4repair_space>server<seq2seq4repair_space>declaration<seq2seq4repair_space>" + value ) , reader . getLocation ( ) ) ; } name = value ; break ; } case GROUP : { group = value ; break ; } case AUTO_START : { start = Boolean . valueOf ( value ) ; break ; } default : throw ParseUtils . unexpectedAttribute ( reader , i ) ; } } } if ( name == null ) { throw ParseUtils . missingRequired ( reader , Collections . singleton ( NAME ) ) ; } if ( group == null ) { throw ParseUtils . missingRequired ( reader , Collections . singleton ( GROUP ) ) ; } final ModelNode address = parentAddress . clone ( ) . add ( SERVER_CONFIG , name ) ; final ModelNode addUpdate = Util . getEmptyOperation ( ADD , address ) ; addUpdate . get ( GROUP ) . set ( group ) ; if ( start != null ) { addUpdate . get ( AUTO_START ) . set ( start . booleanValue ( ) ) ; } list . add ( addUpdate ) ; boolean sawJvm = false ; boolean sawSystemProperties = false ; boolean sawSocketBinding = false ; final Set < String > interfaceNames = new HashSet < String > ( ) ; while ( ( reader . hasNext ( ) ) && ( ( reader . nextTag ( ) ) != ( XMLStreamConstants . END_ELEMENT ) ) ) { final Element element = Element . forName ( reader . getLocalName ( ) ) ; switch ( element ) { case INTERFACE_SPECS : { parseInterfaces ( reader , interfaceNames , address , list , true ) ; break ; } case JVM : { if ( sawJvm ) { throw new XMLStreamException ( ( ( element . getLocalName ( ) ) + "<seq2seq4repair_space>already<seq2seq4repair_space>defined" ) , reader . getLocation ( ) ) ; } <START_BUG> parseJvm ( reader , address , list , new HashSet < String > ( ) ) ; <END_BUG> sawJvm = true ; break ; } case PATHS : { parsePaths ( reader , address , list , true ) ; break ; } case SOCKET_BINDING_GROUP : { if ( sawSocketBinding ) { throw new XMLStreamException ( ( ( element . getLocalName ( ) ) + "<seq2seq4repair_space>already<seq2seq4repair_space>defined" ) , reader . getLocation ( ) ) ; } parseSocketBindingGroupRef ( reader , address , list ) ; sawSocketBinding = true ; break ; } case SYSTEM_PROPERTIES : { if ( sawSystemProperties ) { throw new XMLStreamException ( ( ( element . getLocalName ( ) ) + "<seq2seq4repair_space>already<seq2seq4repair_space>declared" ) , reader . getLocation ( ) ) ; } parseSystemProperties ( reader , address , list , false ) ; sawSystemProperties = true ; break ; } default : throw ParseUtils . unexpectedElement ( reader ) ; } } } private void writeDomainController ( final XMLExtendedStreamWriter writer , final ModelNode modelNode ) throws XMLStreamException { } private void writeServers ( final XMLExtendedStreamWriter writer , final ModelNode modelNode ) throws XMLStreamException { } }

Fix:
parseJvm ( reader , address , list , new HashSet < String > ( ) , true ) ;